ALIFETIME OF working cattle on 50 square miles
of rugged land 45 miles north of Tucson has taught Virgil Mercer
more than most men will ever know about the traditions of ranching.

But these days when the 70-year-old Mercer rises at sunup and
heads out to work his herd, tradition is the last thing on his
mind.

He angles past his horse corral and climbs into his "aerial
pony," the ultralight aircraft he uses to perform most of
the everyday ranch work he once did on horseback.

Strapping on a pilot's helmet and goggles, Mercer fires up the
52-horsepower engine and lifts off from one of four dirt runways
that crisscross an old alfalfa field behind the ranch.

"I'm a traditionalist, sure," says Mercer, whose family
has worked the Campstool Ranch for three generations. "But
I'm also a survivalist. We had to find a way to keep the family
ranch going. What I do in two hours in the ultralight would take
at least three days on horseback."

In his early morning tour, Mercer soars over rugged canyons and
hillsides looking for dead or injured cows, evidence of vandalism,
dried up ponds or any other sign of trouble.

The ultralight flies so slowly and so low that Mercer can spot
details on the ground, down to watching cottontails scampering
beneath his wings. "I can see a water break two feet wide,
that's how close to the ground I am," he says.

At roundup time, Mercer teams with his oldest son, Gary, who
flies a helicopter. They are a tandem in the sky, communicating
by two-way radio, swooping down over cattle to move them this
way and that. To help the doggies along, Mercer sounds a horn
that emits an ear-piercing wail from his plane.

A few years ago, roundup at the Campstool took 14 days, 10 cowboys
and at least 30 horses. Today, with Mercer in the ultralight and
Gary in the chopper, they do the same job in three days. The technique
works so well that they're sometimes hired for roundups at neighboring
ranches.

Money drove the Mercers into the air. Like all ranchers, they
saw expenses spiraling and profit margins shrinking and looked
for ways to cut costs.

At one time, they kept watch over the land from a Cessna
180, but that type of plane operates at high speeds and high altitudes,
so its value for ranch work was limited. After that, they moved
to pickup trucks, motorcycles, the helicopter, and in 1987, an
ultralight.

"The system we have now took a while to evolve, but
the money we save compared with using horses is impossible to
calculate," said Gary, who flew choppers in Vietnam. "But
the key to doing it by air is having pilots who understand cows."

With the elder Mercer at the stick, the ultralight gets a heavy
daily workout. It's not a job for the weak of spirit. The plane
and pilot combined weigh less than 400 pounds, so the awkward
contraption of aluminum poles and Dacron-covered wings is an easy
target for even the mildest gust of wind.

The plane Mercer uses has no windshield. In winter he wears up
to four layers of clothing, a ski mask, gloves. Still, he nearly
got frostbite on one hand from the chill whip of desert winds.

"In my flight suit I look like the Pillsbury Doughboy,"
Mercer said. "But you can still get hypothermia up there."

Even so, it's safer than riding a horse. He estimates that he's
broken 12 bones, gotten his face crushed and had several stays
in the hospital from bouts with temperamental horses.

In four years of flying the ultralight, he hasn't suffered an
injury, even though he once crash-landed on a ridge. Son Virgil
Jr.'s luck has held up even better.

"I've crashed the plane four times and all I got was one
scratched knee," said Virgil Jr., a copper miner. "Heck,
that proves it's safe."

Both said that if the engine quits, the plane, initially designed
as a glider, comes down slowly and can be landed at 20 m.p.h.

And a crash landing isn't likely to deter Mercer. In the Pacific
during World War II, a mortar blast knocked out one of his eyes.
When he got home, people kept telling him what he couldn't do
because of the injury.

"I did everything they said I couldn't, including fly with
one eye," he says. "I'm the eye in the sky, literally."

One of the pluses of Mercer's work is the view. From his open-air
perch, he has traded winks with red-tailed hawks, buzzed curious
black bears and watched mountain lions stalk

"Oh, it's so beautiful," he says, "the way the
land curves, the streams."

More than that, Mercer figures using the ultralight instead of
horses will add 10 years of productive work to his life. The time
it saves has allowed him to take long vacations overseas, something
he couldn't consider previously.

One thing about flying the ultralight worries him, however.

"Sometimes whole flocks of buzzards are up there riding
thermals, and I don't see them until the last minute. Scares the
hell out of me. The last thing I need is a head-on with a buzzard."